[in Japanese]

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It is known to measure precision profile with three or more displacement sensors. Serial three point method is very simple particularly but it has some disadvantages that it is difficult to modify the intervals of displacement sensors and the accidental errors accumulate.This paper presents a new measuring method using smoothed serial three point method.This method is improved on serial three point method using smoothing and weighted least square method. In the present paper the influence of smoothing is theoretically clarified in relation to the error with the real profile and the feasibility of this method is verified theoretically and experimentally.

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This article deals with calculation of three-dimensional sphericity values from minimum circumscribing and maximum inscribing centres, although ISO and JIS define two-dimensional sphericity by means of two or three roundness measurements from minimum circumscribing centre. One of the reasons is the difficulties of measuring technique for the whole spherical surface. In this article, the data to be referred is simulated by applying surface harmonics (Laplace's spherical function). Downhill simplex method, one of nonlinear optimization techniques, is applied for search of minimum circumscribing and maximum inscribing centres. Then, their application conditions are investigated. Furthermore, two- and three-dimensional values of the spherical form errors are compared. In the future, further evaluation methods should be studied for actual three-dimensionally measured spherical form errors.

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This paper presents a new non-contact range sensor system which can recognize a discontinuous surface by Artificial Neural Networks. The sensing device is made of 3 individual same sensor units. Each unit consists of an L-figure steel plate, strain gauges and a permanent magnet at the bottom of the L-plate. A distance between the magnet and a target workpiece is measured by detecting the bending strain of the L-plate caused by an attractive force. In order to cope with a step and a hole as discontinuous surfaces, a hierarchical Artificial Neural Network system with Error Back Propagation method is introduced. The input data to ANNs is the sampled serial values of relative ratio change of each sensor unitis output voltage. The first ANN distinguishes the kind of surfaces. After then, the same input data are handed to each special ANN for a step or a hole as the second ANN. The second ANN detects some metric parameters of a form feature, e.g. height and direction of step. Through the experiments of shape recognition to continuous and discontinuous surfaces, the effectiveness and validity of the sensor system developed have been verified.

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A non-destructive testing technique for a crack existing randomly on a ferrite surface has been developed. Wher the sample is immersed into the volatile solvent, the solvent penetrates into the crack. The surface of sampl? becomes dry quickly, however the solvent remains in the crack and evaporates slowly. The crack is detected independently its position by detecting the evaporating gas from the crack. A FID (flame ionization detector) iE used to detect the extremely thin solvent gas. The optimum treatments from immersion treatment to sealing treatment are studied using several samples with the crack width from 0.003 mm to 0.06 mm. A lot of cracks ar? tested using the experimental apparatus. Experimental results show that a linear relationship is established between crack width and S/N ratio, and the detectable crack length varies inversely with the crack width, fot example in case the surface area is 250 mm², the minimum detectable length with crack width 0.05 mm is 0.3 mm and that with 0.003 mm is 1.4 mm.

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This paper describes the real-time measurement of in-plane vibration using a laser speckle interferometer with the double-aperture method. To detect the in-plane vibration in real-time, a new data processing system with an analog electronic circuit for calculating Fourier coefficients is proposed. The phase angle of the frequency component of interference fringes, which corresponds to the in-plane displacement of a target irradiated by a laser, is directly detected. The measurement system composed of the proposed data processing system and the laser speckle interferometer was applied to measure the in-plane vibration of a target excited by a piezoelectric actuator; the vibration displacement of about 5μm was detected with a sampling frequency of 470Hz and within a measuring error of ±0.5μm.

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A zone-plate interferometer using a diffraction light of (0, 0) and that of (1, 1) is developed. The interferometer enables to measure shape error of mirrors with large numerical aperture and steep asphericity. A procedure for the precise measurement of the shape error is investigated. When a flat mirror is used as a reference mirror, the interferometer enables to measure shape of mirrors with a hole at their center. A spherical mirror and a paraboloidal mirror were measured by the improved interferometer.

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This paper deals with a linear direct drive mechanism of an electrode for electrical discharge machining (EDM) utilizing elliptical movement. This device has two elliptically moving units with piezoelectric elements. It drives the electrode by pinching the electrode synchronously. The electrode moves several micrometers in each cycle with the response of kilohertz order. A locus of a driving pad of the elliptically moving device is examined in experiments and in the calculation with the finite element method. The figure of the locus depends on the difference of the stiffness of each moving unit. The frequency at minimum movement of the electrode is almost the same of the resonance frequency of the electrode in bending mode. Holes of 1 mm in diameter can be machined with the device in a stainless steel plate of 0.1 mm in thickness in 30 s. Electrode feeding devices for machining small holes can be miniaturized and their response can be improved with this mechanism.

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This study considers the motion and the following transient force during attraction of an electromagnetic contactor. The results obtained are as follows. (1) The dynamic load factor of the transient force F_smax produced on a support plate to that F_rmax produced in a cushion rubber shows such the tendency as the parabolic characteristic, which puts the axis with k₄ into a principal axis, with the increasing of the spring constant k₄ of the support plate. The dynamic load factor to k₄ more than 5 k N/mm can be approximately treated as 1. (2) The transient forces F_rmax and F_rmax increase like a function of the second degree with respect to the attraction velocity v_m of a movable core. v_m fluctuates within about 7 times with making phase θ of electric source voltage. Therefore it is effective for the transient force reduction that θ is controlled to be constant within allowed attraction time.

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This paper investigates theoretically the sensitivity of spark location measurement in EDM processes and gives useful information which can contribute to improvement of the measuring sensitivity. The spark location measurement is carried out with the branched electric current method, in which the discharge current is supplied to the electrode through several branched wires, and each spark location is obtained from the ratio of the branched currents. The calculated calibration curve which relates each spark location to the distribution of the branched currents is obtained from the finite-difference analysis of the electric potential distribution in the electrode considering the contact resistance of the feeding points where the branched wires are connected to the electrode. In the course of the analysis, the influences of the contact resistance at the feeding points, the shape of the electrode, and the feeding position on the sensitivity, are studied and the following conclusions are obtained : (1) Although the contact resistance at the feeding points cannot be neglected, it is possible to get the calculated calibration curve which coincides well with the measured calibration curve by taking the contact resistance, which is measured experimentally, into account. (2) A hollow electrode is more effective to improve the sensitivity when a thicker electrode is used. (3) It is possible to get a higher and more uniform sensitivity by feeding the current at the top of the hollow electrode rather than at the bottom.

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In order to synthesize films at low substrate temperature, an apparatus using Penning ion source has been developed and the performance of this apparatus has been discussed. A superconducting magnet has been used to produce magnetic field of up to 7 T, that is impressed on glow discharge. As a result, this newly type of a CVD apparatus can generate stable glow discharge at the pressure of 1 Pa when magnetic field of 1 T affects. Moreover, diamond-like carbon (DLC) films have been synthesized using methane and hydrogen gases, it is found that the apparatus has the possibilities of low temperature synthesis of films.

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Compared to existing metal fiber production methods. coiled sheet shaving is simple and efficient. Various kind of metals can be used and fiber diameter can he easily adjusted. But one major disadvantage of the method is that fiber sticking occurs, which makes it difficult to produce fine and uniform fibers, and put the method to practical application. This investigation was conducted to clarify the causes of fiber sticking in coiled sheet shaving. Experiments were performed with metals currently used. The results showed that fiber sticking is mainly caused by metallic adhesion resulting from the heat and pressure produced during shaving. Experiments on method for reducing sticking were also performed.

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A thin Si diaphragm, which can be easily deformed into a concave shape by applying an electrostatic force, can be used as a dynamic focusing mirror. A diaphragm mirror which has a uniform thickness produces large aberrations because its deformation is not optically ideal. To reduce the aberrations, an optimum thickness profile is calculated by FEM analysis and the profile is created using a unique processing method; initially, photoresist on a Si substrate is exposed to a specific energy profile through a mask made by dither method. The photoresist is then formed a specific curved shape. Optical Fourier transform is also applied during the exposure to smooth it. Finally, it is transcribed to the Si substrate by dry etching in CF₄ /O₂ plasma. The processed shape matches the calculated one with only several sub-microns deviations. The resolving power of the optimum thickness mirror is much higher than the uniform thickness mirror in the wide range of the focal length.

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Lubricant applying effect can be defined as improving machinability in cutting large-work hardening-capacity ductile metals such as pure aluminum, pure copper and so on. The effect is achieved by applying a material on the pre-cut surface. Some of the researchers in the field of metal machining often call this phenomenon a kind of Rebinder effect. This report shows that lubricant applying effect is quite different from the Rebinder effect and goes on to reveal the generating conditions and factors controlling the extent of the effect. This effect can be explained in terms of assisting shear deformation under high normal stress and lessening friction between lamella structure by the applied material.

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For an automatic grinding operation, it is necessary to establish a grinding performance database of super abrasive wheels. In this paper, a new rapid grade testing machine based on the ultrasonic coring method is developed in order to decrease the total cost and the period of grinding performance estimation of super abrasive wheels, and its validity is discussed. As the result, it is cleared that this method has good repeatability and is suitable for rapid testing of the grades of super abrasive wheels. Also, the stock removal rates in ultrasonic coring are dependent upon the specifications of abrasive wheels and their MOR values.

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A fundamental concept of DMCM (Design and Manufacturing Communication Model) is proposed. This concept is to represent a design and manufacturing process as a communication activity. An abstractive “process” is introduced as a key concept of the DMCM that represents an information communication between objects. The object is represented as a communication target, and its inner activity is not treated. To accomplish this concept, a resource structure is proposed as a framework to construct a design and manufacturing communication model. In this framework, the model is constructed with a resource that represents several data communication target and communication process. A formal specification language EPDL (Engineering Process Description Language) is proposed. As an example, a design modification work is described.

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This paper represents a new method for evaluating reliability of manipulators by means of probability of task achievement. Since, articulated manipulators have functional redundancies depending on assigned tasks, they may be able to achieve the task even with faulty joints. In the proposed method, reliability is evaluated taking this feature into account. First, the assigned task is resolved into task steps. Success conditions for achieving each step are obtained based on a manipulator model, which is represented in terms of DH parameters. Next, a success condition of whole task is computed from those of task steps. Finally, the probability of task achievement is evaluated by specifying failure rates of joints in the success condition of whole task. An illustrative example shows the evaluation of a seven DOF manipulator applied to an inspection task.

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In order to improve machining efficiency, it is necessary at each cutting process to select the optimum tool. Therefore, the importance of tool management which considers the features of each cutting tool has been recognized. In the 1st report, a structural model based on a neural network was proposed to estimate the rest of tool life time, and it is one of the most important information on the management. In this paper, the tool management system is proposed to select the most appropriate from a collection of cutting tools. This system consists of a data base block, estimation block and tool selection block. The data base block is in charge of the information (e.g. tool geometry, rest of tool life time, measurement value such as cutting force) on tool selection. The estimation block is composed of the three neural networks for estimating the information at the early turning, latter turning or life time under the given machining conditions. The tool selection block decides the order of selection with the information integration method. The following became clear after the investigation : (1) The estimated information by the networks agreed approximately with the experimental results. (2) The appropriate on the order of tool selection with this method was recognized by comparing the measure of information led from this system with the experiments.

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